Scientists say their latest research indicates that explosive eruptions have been far more common in the past than the gentle outflows seen today.

And they warn that a return to this more violent behaviour would require the permanent evacuation of large areas around the volcano.

Kilauea would simply be too dangerous.

"We've found from our work that over the past 2,500 years, which is about as far back as we can see, Kilauea has been in an explosive mode about 60% of the time and in a lava-producing mode, such as it's in now, only about 40% of the time," explained Dr Don Swanson from the US Geological Survey's Hawaiian Volcano Observatory, Hawaii National Park.